Email tools

The email tools let an assistant run your email channel end to end: connect a sending domain, write templates, build automated emails such as abandoned checkout, schedule broadcasts to a segment and watch deliverability. They are on the VYG agents server, not on https://api.vyg.app/mcp:

https://agents-mcp.vyg.app/mcp

claude mcp add --transport http vyg-email https://agents-mcp.vyg.app/mcp

Your assistant signs you in the first time it connects. Every tool works on the brand you signed in to; no tool takes a brand id. Lists return up to 25 items by default and at most 100, with a next_cursor to pass back as cursor for the next page.

A full setup, step by step

1. Connect a sending domain. email_domain_add returns the DNS records to publish. After publishing them, email_domain_recheck confirms the domain. Use a subdomain such as mail.yourstore.com.
2. Add your business address. Every marketing email must show a postal address. email_brand_address_get shows what is on file and email_brand_address_set saves it. You can also set it in VYG under Settings → Email → Business address.
3. Write a template. email_template_create saves it live as soon as it passes the checks below. email_template_preview shows it with sample data and email_template_test_send sends one copy to your own inbox.
4. Build the automation. email_flow_create with the checkout/abandoned trigger and an Email step (or a Resend step) creates the flow paused. email_flow_activate starts it.
5. Watch results. email_send_list, email_deliverability_stats and email_sending_status.
6. Broadcast to a segment. email_segment_create, then email_broadcast_create with a send time. email_broadcast_pause stops it at any time.

Example requests:

Connect mail.acme.com as our sending domain and tell me which DNS records to add.

Create an abandoned checkout email that lists the cart items with images, send me a test, then turn it on
one hour after checkout is abandoned.

Email everyone in the VIP segment our restock template next Tuesday at 9am New York time.

Templates

email_template_create and email_template_update run the same checks before saving. If a check fails nothing is saved and the assistant gets the list of problems to fix:

• a subject and an HTML body;
• an unsubscribe link whose address is {{unsubscribe}};
• no <script> tags, on… event handlers or javascript: links;
• an HTML body under 100 KB.

A missing postal address and unknown variables come back as warnings. Saved templates are live and can be used by flows and broadcasts right away. Templates follow the same rules whether they are saved here or in VYG under Settings → Email. Editing a template keeps its id, so everything that uses it picks up the change on its next send. The version number goes up when a live template changes. An edit that would overwrite someone else's newer save is refused, so the assistant reads the template again and retries. Pass expected_version to refuse the edit whenever the template is no longer at the version the assistant read. email_template_archive retires a template: anything still pointing at it stops sending until it uses a live template. Archived templates cannot be edited.

Variables

Write variables as {{name}} in the subject, body or plain text. email_template_variables_list returns this list to the assistant.

To repeat a block for every item in the cart, wrap it in {{#each products}}…{{/each}}. Inside the block the product.* variables refer to the current item. Outside a block they refer to the first item in the cart.

Business address

Anti-spam law requires every marketing email to show the sender's postal address, which templates add with {{brand.address}}. email_flow_activate, email_broadcast_create and email_broadcast_resume refuse to go live until your brand has one.

email_brand_address_set takes line1 (street address), city and country, which are required, plus optional line2, region (state or province) and postal (postal or ZIP code). It replaces the whole address and returns the line that emails will show, such as 100 Main St, Austin, TX 78701, US. Every part is trimmed and must be plain text without < or >. If a part is missing or invalid, nothing is saved.

Automated flows

email_flow_create builds a flow with a trigger, an optional wait and one email step. The trigger is either a store event, trigger_event (checkout/abandoned or order/delivered, which need a connected Shopify store), or one of your Custom E-Com events, custom_event: { type }, such as hq_checkout_abandoned. Your own system sends those events to VYG. If two providers define the same event type, add provider. For a brand without Shopify, the error lists its custom event types.

The email step is one of:

• Email step. Sends a live VYG template from a verified domain. Pass from_domain, or leave it out to use your first verified domain.
• Resend step. Sends a template from your own Resend account. Pass the Resend template id, the from address and variable_mappings from each Resend variable to a data path such as contact.first_name or event.checkout_url. Resend must be connected in VYG.

New flows are saved paused. email_flow_activate checks that every Email step has a live template and a verified domain and that your brand has a postal address, then starts the flow; if something is missing it changes nothing and lists the problems. Starting a flow requires an active VYG subscription. email_flow_pause stops it. email_flow_update_node changes the template, domain or Resend settings, also on a running flow. email_flow_delete removes a paused flow or broadcast that has never sent anything. It stops for good at once and disappears from the email tools. In VYG it stays listed as paused, with [Deleted] before its name.

Message variants are optional. email_flow_variant_add adds another live template that competes with the step's own template, and better performers get more traffic over time. A step without variants sends its own template to everyone.

Segments and broadcasts

A segment is either a list of up to 5,000 addresses or a customer-data condition, and it always contains only your customers. email_broadcast_create sends a live template to a segment once at send_at, or repeatedly with first_send_at and every_hours (24 or more). Only subscribed recipients are mailed; unsubscribed and suppressed addresses are skipped. email_broadcast_pause stops a broadcast, including a send already in progress, and email_broadcast_resume restarts it, optionally at a new time.

Monitoring

• email_send_list: recent sends with recipient, status and the flow or broadcast that sent them. Test sends are left out unless include_tests is true.
• email_deliverability_stats: delivery, bounce and complaint rates over the last 7 days, for the whole brand or one flow, plus any alarm that would pause sending.
• email_sending_status: each domain's verification, its daily warm-up limit and whether sending is paused. New domains start with a small daily limit that grows as they warm up.
• email_suppression_list: addresses that are never emailed, with the reason.
• email_catalog_status: whether your product catalog has synced, with product counts and the last error. Until the first sync completes, {{product.image_url}} is blank. The catalog refreshes automatically, and email_catalog_sync_request asks for a full sync sooner. The request is queued and runs within about 15 minutes. The current catalog stays in use until the new sync completes. A brand without a connected Shopify store has no catalog: both tools return applicable: false, and sending is not affected.

All email tools

Ask your assistant to show what it is about to change and to wait for your confirmation before it runs a tool that makes changes, especially email_flow_activate and email_broadcast_create, which send to real customers.

Next steps

• Tool catalog for everything on https://api.vyg.app/mcp
• Other clients to connect clients other than Claude